Grinding-machine.



0. s. WALKER. GRINDING MACHINE.

' APPLICATION FILED NOV. 29, 1909. 1,091A07. Patented Mar. 24, 19-1;

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0. S. WALKER.

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APPLICATION TILED NOV. 29, 1909 Patented Mar. 24, 1914.

2 SHEETS-SHEET 2.

Invenfor OAKLEY SLWALKEB, OF WORCESTER, MASSACHUSETTS.

GRINDING-MACHINE.

Specification of Letters Patent.

Patented Mar. 24, 1914.

Application filed November 29, 1909. Serial No. 530,290.

To (1] l whom it may concern:

Be it known that I, OAKLEY S. WALKER, a citizen of the United States, residing at Worcester, in the county of W'orcester and Commonwealth of Massachusetts, have invented a new and useful Improvement in Grinding-lllachines, of which the following is a specification, accompanied by drawings forming a part of the same, in which- Figure 1 represents aside elevation of a grinding machine embodying my present invention, Fig. 2 is a central, vertical, sectional view, Fig. 3 is a plan view of a system of speed reducing gearing between the grinding wheel and the work supporting table. Fig. 4 .is a side elevation of the vertically sliding head supporting the abrading wheel, and shown in its raised position. Fig. 5 is a plan view of the work supporting table showing the position of the abrading wheel relative thereto, and Fig. 6 is a sectional view on a larger scale of the annular rim inclosing the work supporting, table.

Similar reference characters refer to similar parts in the different views.

My present invention relates particularly to that class of grinding machines in which the'work supporting table comprises a magnetic chuck for holding the work in proper position while it is being subjected to the action of a revolving abrading wheel, and it has for its objects to facilitate the adjustment and manipulation of the machine, and

to render certain operations automatic, and these objects, among others, hereinafter pointed out, are accomplished by the construction and arrangement of parts as hereinafter described and set forth in the annexed claims.

Referring to the accompanying drawings 1 denotes a hollow supporting stand or framework upon which the operative parts of the machine are mounted, 2 is a driving shaft journaled in the base of the machine and provided with'tight and loose pulleys 3 and at. The driving shaft 2 carries within the stand 1 a pulley h-having a belt connection with a pulley 6 upon avertical shaft 7. To the upper end of the vertical shaft 7 is attached a pulley 8 having a belt connecrion with a pulley 9, attached to a vertical grinding wheel shaft 10 11, said head having a s iding movement in ournaled in a heady pinion mechanism comprising a'rack 13 and in on 14 carried upon a spindle 15 proecting through the head 11 and provided on its outer end with a lever handle 16' thereby enabling the head 11 to be raised and lowered by the operator.

The lower end of the shaft 10 carries an abrading wheel 17 which is moved toward and away from the work 18 held u on a rotating-work supporting table 19. The work supporting table 19 is carried upon the upper end of a shaft 20 which carries a belt pu ley 21 having a belt connection with a pulley 22, attached to a vertical spindle 23 iaving a geared connection with the verti. cal shaft 7 through a system of speed reducmg gears, comprising the gears 24, 25, 26,

vertical ways 12, by means of a rack and 27, 28, 29 and 30, shown 111 plan view in Fig. 3, causing a slow rotative movement to be imparted to the work sup orting table. The shaft 20 is journaled in a s iding bracket 31 capable of a vertical sliding movement in ways 32 and supported at any desired elevation by means of a screw 33 journaled in the bracket 31 and engaging a nut 34 held from rotation in a step 35, The screw 33 is connected by gears 36 and 37 with a short spindle 38 having its outer end 39 poly onal to receive a wrench or crank handl e by which the screw 33 may be rotated in order to raise or lower the work supporting table.

The work supporting table 'in the present instance comprises a magnetic chuck 40 of the usual and well known form of construction with its face forming the work supporting table 19. The magnetic chuck has an electrical connection through the brushes 41 and 42 with an electrical switch 43 mounted on the side of the upright stand or frame work 1. The switch is provided with a pair of contact surfaces 44 and 45 adapted to contact with a vertically moving switch bar 46 carried by the slidinghead 11, whereby there is completed an electric circuit by which the magnetic chuck is energized whenever the die 1 the as ':h collar 63, thereby 65 20 ruimiuu of the Work support i I Qeifehy the pol-a" us-ih Witch bur :l

Wlllll ihe 3211' The contac f such leu veiii m8 5 Attached to the sliding bucket 3i upon which is mounted a.

W, 67. able 19 is cylindri- .:.h a projecting flange mlppOliGi'l an annular rim ruling flange '50, which 0veri'inulai' flange prujeetin a. cup shaped.

the rotating work ll ute? is (li reeled. through wvk held upon the he Water fed (in "s caught at the case 72 and re 85 [if my ")ZOVGtl gfinding s: Fewer is applied ifs $3 to the Vertical "rapid rotary metion .ie pulleys 8 and 9 to the 1 b 16 and. abracling motion is impartedreducing gears shown mm the shaft 7 t0 is raised in hhe lug: prsvifling space 21;; wheel "J anti the sursupportihg iahle for the Ni 1; on the latter. The then placed upeh the surface of u pcitiug table as shown in Fig.

' slate of rest The lo-yvei'ecl by means of e TESL pail pusit L he T381": l-- ll 5 strikes the Work b he *1 s the clewuwaii moion of the (l 11 The mugnetis chuek becen'ies enei-- 1m 'ii i by the centuei Hie switch-bar 46 b the lower pair ef eontect surfaces 44 4 .The depressionnf :he sliding head lowers the pulley 22 unt l. its clutch meruengages the clutch cellar 63 Whichis rushing shafi, 0b, L 1 w i i rm b9 jrmifled zizach (l to :the spineile :23, causing a rotary l IHUHGH .50 be impurfied to the Work support-- Lug fable "through the belt pulleys 21 and 22.

l The rotation ui. the Work supporting table unnies the pieces of Work 18 successively beneath the lowey surface of the ahrnding Wheel 17 which is preferably cup shapecl 31s the grinding continued the sliding (l Wit-l). a clutch nulley is allewecl clutch collar 63 k a Tahitian CL the head heuu 11 is ei'mitted to descend until it through the reaches the hxed stop which checks its described 1:0 5 downward moyei'ueula and determines the *ulley to sl kness of the finished Work. The sliding ".t of en hem 11 iggthen raised, causing the pulley 5:2 01 the 11; new ceimeciiugg iiit the eel memo? 22 to become disconnected from its driving spindle 23, again checking the rotation of the work supporting table. The upward movement of the sliding head 11 also carries the switch bar 46 out of contact with the surfaces 44.- and s5 and moves the switch bar across and in contact with the upper pair of contact surfaces 47 and 48, which by} crossed wires reverse the polarity of the magnetic chuck, thereby demagnetizing the chuck and allowing the work to be removed. The length of the contact surfaces 47 and 48 is sufficient to allow the contact to be maintained between them and the switch bar 46 a sufiicient length of time at the speed at which the sliding head is moved upwardly to just effect the demagnetizing of the chuck.

A variation in the thickness of the work ground may be accomplished by varying the position of the stop 52 or by raising or lowering the bracket 31 in which the work supporting table is journaled. The, annular rim G9, a portion of which is shown on a larger scale in Fig. 6, is adjustably supported on the projecting flange (38 by means of screws 75 carried by the rim 69, with their tips resting upon the flange 68, thereby enabling the rim (SO'to be raised above the horizontal plane of the face of the work supporting table 19 in order to form an annular rim to prevent the sidewise removal of work from the work supporting table. The use of the fan blower 55 causes a current of air to pass through the interior of the magnetic chuck and prevents an accumulation of moisture therein. The fan 65, in the pres ent instance, is driven independently by the motor (36, but it might obviously be'connected through a belt connection with a driving pulley upon one of the rotating shafts by such a connection as would permit the up and down movement of the fan, or the fan might be held in a fixed position and be connected with the hollow shaft 90 of the magnetic chuck by a flexible connection.

All the operations of the machine are antomatically performed with the exception of raising and lowering the abrading wheel, placing the work upon the work supporting table and removing it therefrom. Each rising movement of the head 11 withdraws the abrading wheel from the work, automatically stops the rotation of the work sup porting table, and demagnetizes the chuck +0, while the downward movement of the head 11 brings the abrading wheel into oper ative position, causing a downward movement of thewheel, as the thickness of the work is reduced until'the descent of the head 11 is checked by the stop 52. Simultaneously with the downward movement of the head 11 the magnetic chuck becomes energized through the automatic switching mech anism and the work supporting table is started and caused to slowly rotate in order to carry the pieces of work successively beneath and in contact with the abrading wheel.

To place the work in position and automatically grind the same to any predetermined thickness only rcquires the raisingand lowering of the abrading wheel, allowing the entire surface of the work supporting table to be covered with pieces of work, as the periphery of the abrading wheel overlaps the ccntcr of the rotating work supporting table. As the abrading wheel 17 is cup shaped the grinding operation is confined to the narrow surface forming the side of the wheel rim, so that the speed of the grinding surface of the wheel in contact with the work is substantially uniform.

I claim,

1. In a grinding machine, a work supporting table having an outwardly extending flange with a rim depending therefrom, a casing surrounding said table, means for admitting water upon the work held on said table. a shaft supporting said table and passing through said casing, and means arried by said casing and projecting into the space between said table and said depending rim, for preventing access of water to said shaft.

2. In a grinding machine, a rotatable work supporting table, a grinding'wheel in operative relation to said table, means for raising and lowering said grinding wheel, and an automatic attachment between said grinding wheel and said rotatable table arranged to stop the rotation of said table when said wheel is raised, and to start the rotation of said table when said wheel is lowered into operative position.

3-. In a grinding machine, a bracket vertically slidable in ways in the framework of the machine, a shaft journaled in said bracket, a work supporting table secured to the upper end of said sh'aft, means for rotating said shaft. and means for adjusting said bracket vertically.

4. In a grinding machine, a fixed framework having yertical ways, a head slidable on said ways, a shaft journaled in said head, a grinding wheel carried by said shaft, vertical ways in said framework below said grinding wheel, a bracketvertically adjustable in said lower ways, a shaft journaled in said bracket with its axis parallel with the axis of said grindingwheel, a work holding table carried by said shaft and means for rotating said shaft.

in a grinding machine, work supporting means having an interior chamber, a shaft secured t o aid work supporting means, having aborc in connnunieation with said chamber, and means for forcing air through the bore of said shaft into said chamber.

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i t0 the 91 and sand grmdin W to hold and support the work, grinding means, means for shifting said grinding means into and out of operative position with respect to said work holding means,

' and means, operated by said shifting means for rendering said work holding means active or inactive.

21. In a grinding machine, means for holding the work, grinding means, means for shifting said grinding means into operative position with respect to the work, and means, actuated by said shifting means, for rendering said work holding means active.

22. In a grinding machine, means for holding the work, grinding means, means for shifting said grinding means out of operative position with respect to the work and means, actuated by said shifting means, for rendering said work holding means inactive.

23. In a grinding machine, means for holding the work, grinding means, means for shifting said work holding means and said grinding means into and out of operative position with respect to each other, and means, actuated by said shifting means, for rendering said work holding means active or inactive.

24:. In a grinding machine, movable means for holdin the work, grinding means, mean; for s ifting said work holding means and said grinding means into and out of operative position with respect to each other, and means, actuated by said shifting means, for starting and stopping the movement of said work holding means.

25. In a grinding machine, a rotatable work supporting means, a grinding means, means for'shifting said work supporting means and said grinding means into and out of operative position with respect to each other, and means actuated by said shifting means for starting and stopping the rotation of said work supporting means.

26. In a grinding machinepa movable work supportin means, grinding means, means for shifting said work supporting means and said grindingmeans into and out -of-opcrative position with respect to each other, means, actuated by said shifting means, for startin and stopping the movement of said wor supporting means, and means, also actuated by said shifting means, for rendering said work holding means active or inactive.

27. In a. grinding machine, a rotating shaft, a rotatable work supporting table, a clutch mechanism adapted to operatively connect said shaft with said table, a grinding wheel rotated by said shaft, means for shifting said grinding wheel and said table into and out of operative position with respect to each other, and means, actuated by said shifting means, for engaging and disengaging said clutch mechanism.

'28. In a grinding machine, a magnetic work retaining means included in an electric circuit, a grinding means, means for shifting said grinding means and said work retaining means into and out of operative position with respect to each other, and means, operated by said shifting means, for opening and closing said electric circuit.

29. In a grinding machine, a work supporting table comprising a magnetic chuck included in an electrical circuit, a switch in said circuit, a grinding wheel, means for shifting said grinding wheel and said table into and out of operative position with respect to each other, whereby the switch is operated to close and open said electrical circuit.

30. In a grinding machine, a fixed framework, a work supporting table, comprising a magnetic chuck included in an electrical circuit, a head slidable in said framework, a grinding wheel carried by said head, means for moving said head to carry the grinding wheel toward and away from said table, a reversing switch in said electrical circuit, and means carried by said head for closing and opening said switch to energize and deenergize said chuck upon movement of said head.

31. In a grinding machine, a work supporting table, comprising a magnetic chuck included in an electrical circuit, a grinding wheel, means for shifting said grinding wheel into operative position with respect to said table, and means, actuated by said shifting means, adapted to close said electrical circuit and thereby energize said magnetic chuck.

32. In a grinding machine, a work supporting table, comprising a magnetic chuck included in an electrical circuit, a grinding wheel, means vfor shifting said grinding wheel out of operative position with respect to said table, and means, actuated by said shifting means, adapted to open said electrical circuit and thereby deenergize said magnetic chuck.

33. In a grinding machine, a work supporting table, comprising a magnetic chuck included in an electrical circuit, a grinding wheel, means for shifting said grinding wheel and said table into and out of operative position with respect to each other, and means, actuated by said shifting means, adapted to close and open said electrical circuit, and thereby energize and deenergize said chuck.

34. In a grinding machine, a work supporting table, comprising a magnetic chuck included in an electrical circuit, two pairs of contact pieces in said circuit in reversed relation, a grinding wheel. means for shifting said grinding wheel out of operative ppsition with r spect to said table, and 

